1. Field of the Invention
This invention concerns converting pressure variations into electrical energy through the agency of hydraulic and/or mechanical devices and more particularly concerns the various causes or pressure variations and how their energy may be more efficiently converted into electrical energy.
2. Prior Art
Piezoelectric inventions convert pressure variations directly into electrical energy but their efficiency is very low and charging piezoelectric material is expensive.
Bourdon tubes that transmit power have been proposed. See my U.S. Pat. No. 6,781,253. But the use of the invention is restricted to surface and subsurface ocean wave energy or the input. Wind and subsurface ocean currents are examples of types or energy input for this invention. They possess mechanical energy. The two relevant components of mechanical energy are pressure energy and kinetic energy. Up to now only some few efforts have been made to convert the pressure-energy o these two fluids into electrical energy. Yet the extractable pressure energy of these two fluids as they naturally occur is far greater than their extractable kinetic energy. Hydroelectric turbine generators are a prime example of devices which convert pressure energy into electrical energy. A pressure head is artificially built up in differentiation with the pressure of the surrounding atmosphere. Theoretical power output is calculated as this pressure difference multiplied by the rate of flow.
The relevant technology for converting the pressure energy of the wind into electrical energy is U.S. Pat. No. 5,709,419 to Roskey. Pressure energy is converted to kinetic energy by using a Venturi flume with the kinetic energy compounded with the use of a manifold. The manifold lies outside the Venturi flume so the advantage of using a manifold is minimized since pipe friction can be very great unless large pipes are used.
For converting the pressure energy of subsurface ocean currents into electrical energy the U.S. patent most relevant to this invention is U.S. Pat. No. 6,568,181 to Hassard et. al. Here an airflow is drawn through an air turbine ashore from a pipe to an offshore Venturi tube's throat, as may be observed with a manometer. The speed of the current as it is accellerated through the throat determines the speed of the airflow. But to avoid large energy glosses through the airpipe due to friction a large and expensive pipe is needed.